has to change planes at Dubai
That sounds expensive .... all those shops selling gold!
Seriously, which airline is she flying with? Emirates? If so, when she checks in she should mention that she has not flown before, or changed planes at Dubai. In a nutshell, at Dubai airport, the Emirates staff will look after her and ensure that she knows where to go to get the second plane.
A couple of years ago my parents-in-law flew with Emirates Bangkok-Dubai-Birmingham, and they had not flown internationally before. The Emirates staff were great ...really provided a good service.